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Related papers: Volume comparison by timelike Lipschitz maps

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The paper proposes a notion of volume element for Finsler spaces with metrics of Lorentzian signature, equipped with a time orientation. This notion is based on a slight modification of the idea of Holmes-Thompson volume element working for…

Differential Geometry · Mathematics 2015-01-20 Nicoleta Voicu

The paper proposes extensions of the usual notions of Finslerian volume to time orientable Finsler spacetime manifolds. The basic idea is to replace, in the classical Busemann-Hausdorff and Holmes-Thompson definitions, integration on the…

Differential Geometry · Mathematics 2016-12-30 Nicoleta Voicu

We consider canonical/Weyl-Moyal type noncommutative (NC) spaces with rectilinear coordinates. Motivated by the analogy of the formalism of the quantum mechanical harmonic oscillator problem in quantum phase-space with that of the…

High Energy Physics - Theory · Physics 2023-01-02 B. Muthukumar , Aamir Rashid

We show that the random adjacency matrices induced by the chronological relations and i.i.d. samples of two spacetimes coincide in law if and only if the spacetimes in question are smoothly isometric. A similar result holds for weighted…

General Relativity and Quantum Cosmology · Physics 2025-07-03 Mathias Braun

If $L^x$ is the total occupation local time of $d$-dimensional super-Brownian motion, $X$, for $d=2$ and $d=3$, we construct a random measure $\mathcal{L}$, called the boundary local time measure, as a rescaling of $L^x e^{-\lambda L^x} dx$…

Probability · Mathematics 2020-01-27 Jieliang Hong

In this article, we investigate the volume comparison with respect to scalar curvature. In particular, we show volume comparison holds for small geodesic balls of metrics near a V-static metric. For closed manifold, we prove the volume…

Differential Geometry · Mathematics 2021-02-22 Wei Yuan

Timelike sectional curvature bounds play an important role in spacetime geometry, both for the understanding of classical smooth spacetimes and for the study of Lorentzian (pre-)length spaces introduced in \cite{kunzinger2018lorentzian}. In…

Differential Geometry · Mathematics 2026-01-01 Tobias Beran , Michael Kunzinger , Argam Ohanyan , Felix Rott

Time-like and space-like invariant space-time intervals are used to analyse measurements of spatial and temporal distances defined by two spatially-separated clocks. The time dilatation effect is confirmed, but not `relativity of…

General Physics · Physics 2009-09-01 J. H. Field

Motivated by Schoen's conjecture on the volume functional for closed hyperbolic manifolds, we generalize the volume comparison theorem of Hu, Ji, and Shi and establish a volume comparison theorem for rank 1 symmetric spaces of non-compact…

Differential Geometry · Mathematics 2026-02-10 Jiaqi Chen , Yufei Shan , Yinghui Ye

In this work we provide the full description of the upper levels of the classical causal ladder for spacetimes in the context of Lorenztian length spaces, thus establishing the hierarchy between them. We also show that global hyperbolicity,…

General Relativity and Quantum Cosmology · Physics 2020-10-16 L. Ake Hau , Armando J. Cabrera Pacheco , Didier A. Solis

The apparent times and positions of moving clocks as predicted by both `non-local' and `local' Lorentz Transformations are considered. Only local transformations respect translational invariance. Such transformations change temporal but not…

General Physics · Physics 2011-11-10 J. H. Field

We consider a general class of statistical experiments, in which an $n$-dimensional centered Gaussian random variable is observed and its covariance matrix is the parameter of interest. The covariance matrix is assumed to be…

Statistics Theory · Mathematics 2025-01-17 Cristina Butucea , Alexander Meister , Angelika Rohde

In this research article, we establish some identities and estimates for the operator norms and the Hausdorff measures of noncompactness of certain operators on some lacunary difference sequence spaces defined by Orlicz function. Moreover,…

Functional Analysis · Mathematics 2015-06-19 Ekrem Savas , Stuti Borgohain

I present an analysis of the physical assumptions needed to obtain the metric structure of space-time. For this purpose I combine the axiomatic approach pioneered by Robb with ideas drawn from works on Weyl's "Raumproblem". The concept of a…

General Relativity and Quantum Cosmology · Physics 2010-09-29 Jochen Rau

A Lorentzian manifold endowed with a time function, $\tau$, can be converted into a metric space using the null distance, $\hat{d}_\tau$, defined by Sormani and Vega. We show that if the time function is a proper regular cosmological time…

Differential Geometry · Mathematics 2023-01-26 A. Sakovich , C. Sormani

We introduce an analogue of the theory of length spaces into the setting of Lorentzian geometry and causality theory. The r\^ole of the metric is taken over by the time separation function, in terms of which all basic notions are…

Differential Geometry · Mathematics 2019-11-07 Michael Kunzinger , Clemens Sämann

We study the problem of a temporal discontinuity in the permittivity of an unbounded medium with Lorentzian dispersion. More specifically, we tackle the situation in which a monochromatic plane wave forward-travelling in a (generally lossy)…

Optics · Physics 2025-09-24 Diego M. Solís , Raphael Kastner , Nader Engheta

We develop a new method to estimate the area, and more generally the intrinsic volumes, of a compact subset $X$ of $\mathbb{R}^d$ from a set $Y$ that is close in the Hausdorff distance. This estimator enjoys a linear rate of convergence as…

Metric Geometry · Mathematics 2024-07-22 David Cohen-Steiner , Antoine Commaret

We study Lyapunov vectors (LVs) corresponding to the largest Lyapunov exponents in systems with spatiotemporal chaos. We focus on characteristic LVs and compare the results with backward LVs obtained via successive Gram-Schmidt…

Chaotic Dynamics · Physics 2008-08-05 Diego Pazó , Ivan G. Szendro , Juan M. López , Miguel A. Rodríguez

We construct a Lorentzian length space with an orthogonal splitting on a product $I\times X$ of an interval and a metric space, and use this framework to consider the relationship between metric and causal geometry, as well as synthetic…

Differential Geometry · Mathematics 2023-11-20 Elefterios Soultanis